As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDING GEAR WILL NOT RETRACT WITH LEVER IN UP POSITION, ALL RED (EXCEPT LEFT A) AND ALL GREEN LIGHTS ARE ILLUMINATED. DID NOT HEAR OR FEEL ANY GEAR MOVEMENT. COMPLETED ALL QRH PROCEDURES WITH NO RESULTS AND ALL CIRCUIT BREAKERS CHECKS OK. HYDRAULIC SYSTEM OK. REPLACED LEFT MLG A UPLOCK SENSOR HARNESS, CHECKS GOOD.